JP6530282B2 - Work apparatus and communication control method - Google Patents

Description

  The present invention relates to a work device and a communication control method.

  2. Description of the Related Art Conventionally, when using a wireless communication to remotely operate a working device such as a working robot, the quality of wireless communication between a controller and the working device has been improved. For example, Patent Document 1 discloses a system in which a communication unit on the robot side adjusts the transmission output level of a radio wave based on the reception condition of the radio wave on the controller side of the robot.

  Further, according to Patent Document 2, the communication quality of the wireless communication with the access point falls below the threshold value in the wireless communication apparatus that controls the mobile robot via any one of the plurality of access points. It is disclosed to switch access points accordingly.

Unexamined-Japanese-Patent No. 2010-26947 JP 2012-201202 A

  By the way, high communication quality may be required depending on the situation around the work device. For example, when there is an obstacle around the work robot, it is required to receive an operation command received from the controller without delay in order to avoid a collision with the obstacle. However, although the control methods described in Patent Documents 1 and 2 attempt to improve the communication quality based only on the condition of the communication quality, there is a problem that the surrounding conditions are not considered.

  Therefore, the present invention has been made in view of these points, and it is an object of the present invention to provide a working device and a communication control method capable of adjusting communication quality based on surrounding conditions.

  The work apparatus according to the first aspect of the present invention is a work apparatus that performs work in accordance with remote control from a controller, and includes an environment specifying unit that specifies an environment of a space around the work apparatus; A calculation unit that calculates an allowable delay time that is an allowable communication delay time of the work apparatus based on an environment, and a prediction unit that predicts a future communication delay time of wireless communication with the controller A selection unit that selects a communication function related to the wireless communication based on the allowable delay time and the predicted communication delay time; and a communication control unit that controls the wireless communication based on the selected communication function. Equipped with

  The work device is a movable body, and the work device further includes a speed detection unit that detects a movement speed of the work device, and the calculation unit determines the allowable delay time based on the space environment and the movement speed. It may be calculated.

The selection unit may select a function to limit the number of retransmissions of the packet to be transmitted by the wireless communication, when the communication delay time is larger than the allowable delay time.
The selection unit may select a function of occupying a band in the wireless communication for a predetermined period when the communication delay time is larger than the allowable delay time.

  The selection unit selects one communication method from a plurality of communication methods for performing the wireless communication based on the allowable delay time and the communication delay time, and the communication control unit selects the communication method. The wireless communication may be controlled based on

  A communication control method according to a second aspect of the present invention is a communication control method in which a computer performing work in accordance with remote control from a controller controls wireless communication with the controller, and a space around the computer Determining an allowable delay time which is an allowable communication delay time based on the space environment, and predicting a future communication delay time of the wireless communication. Selecting the communication function related to the wireless communication based on the calculated allowable delay time and the predicted communication delay time; and controlling the wireless communication based on the selected communication function And.

  According to the present invention, it is possible to adjust communication quality based on surrounding conditions.

It is a figure showing composition of a communication system concerning this embodiment. It is a figure showing composition of a work device concerning this embodiment. It is a flow chart which shows a flow of processing concerning selection control of a communication function. It is a figure which shows the correspondence of the radio | wireless environment of a working apparatus, the measured value of communication delay time, and the estimated value of communication delay time calculated using each of several prediction formula.

[Configuration of Communication System S]
FIG. 1 is a diagram showing a configuration of a communication system S according to the present embodiment.
The communication system S includes a work device 1, an access point 2, and a controller 3.

  In the communication system S, the access point 2 is a wireless LAN access point and performs wireless communication with the work device 1. The controller 3 is, for example, a smartphone, and is connected to the access point 2 via a communication network such as a cellular phone line or the Internet.

  The work apparatus 1 is a movable robot disposed under the eaves of a house, a volcanic area, a disaster site, or the like. The work device 1 is a moving body provided with a moving mechanism 11. In addition, the work apparatus 1 includes the imaging unit 12, and when receiving an operation command from the controller 3 via the access point 2, performs various operations such as movement and imaging based on the operation command. The work device 1 transmits the captured image or the like to the controller 3 via the access point 2.

  Based on the environment of the space around itself, work device 1 starts from the time when controller 3 sends an operation command, and allows itself for the communication delay time which is the time until the operation command is actually received. An allowable delay time which is a possible communication delay time is calculated, and a future communication delay time of wireless communication with the controller 3 is predicted. The work device 1 selects a communication function related to wireless communication based on the calculated allowable delay time and the predicted communication delay time, and controls wireless communication based on the selected communication function.

By doing this, the work apparatus 1 selects the communication function to shorten the communication delay time of the wireless communication when the predicted communication delay time is longer than the allowable delay time calculated based on the surrounding conditions. Communication with the controller 3 can be performed based on the communication function. Therefore, the work device 1 can adjust the communication quality based on the surrounding conditions.
Subsequently, the configuration of the work device 1 will be described.

[Configuration of Work Device 1]
FIG. 2 is a diagram showing the configuration of the work device 1 according to the present embodiment. The work apparatus 1 includes a moving mechanism 11, an imaging unit 12, a wireless communication unit 13, a storage unit 14, and a control unit 15.

The moving mechanism 11 includes a wheel, a drive control unit for driving the wheel, and the like, and controls the movement of the work device 1.
For example, the imaging unit 12 captures an image of the front of the work device 1 at a predetermined frame rate, and outputs an image indicating the situation around the work device 1 to the control unit 15.

  The wireless communication unit 13 transmits various information to the access point 2. The wireless communication unit 13 modulates the signal output from the control unit 15 to generate an RF (Radio Frequency) signal, and wirelessly transmits the RF signal to the access point 2 via an antenna (not shown). The wireless communication unit 13 demodulates the RF signal received from the access point 2 via the antenna, and outputs the signal obtained by the demodulation to the control unit 15.

The wireless communication unit 13 includes a prediction unit 131, a selection unit 132, and a communication control unit 133. Details of the prediction unit 131, the selection unit 132, and the communication control unit 133 will be described later.
In the following description, the control unit 15 performs wireless communication with the access point 2 via the wireless communication unit 13.

  The storage unit 14 is configured of, for example, a ROM, a RAM, and the like. The storage unit 14 stores various programs for causing the work device 1 to function. The storage unit 14 may read and store a program stored in a storage medium such as an external memory, or may store a program downloaded from an external device via the access point 2.

  The control unit 15 is configured of, for example, a CPU. The control unit 15 controls various functions related to the work device 1 by executing various programs stored in the storage unit 14. The control unit 15 includes an imaging control unit 151, an environment specifying unit 152, a movement control unit 153, a speed detection unit 154, and a calculation unit 155.

When the wireless communication unit 13 receives the operation command instructing shooting, which is transmitted from the controller 3, the shooting control unit 151 controls the shooting unit 12 based on the operation command. The imaging control unit 151 acquires an image captured by the imaging unit 12. The imaging control unit 151 may cause the imaging unit 12 to always perform imaging in response to the start of the operation of the work apparatus 1.
The imaging control unit 151 transmits the image captured by the imaging unit 12 to the controller 3 via the wireless communication unit 13.

When the wireless communication unit 13 receives the operation command for instructing the movement of the work apparatus 1 transmitted from the controller 3, the movement control unit 153 controls the movement mechanism 11 based on the operation command to control the work apparatus 1. Move it.
Detailed processes of the environment specifying unit 152, the speed detecting unit 154, and the calculating unit 155 will be described later.

[Selection control of communication function]
As described above, the work apparatus 1 selects the communication function of the wireless communication based on the surrounding conditions, and performs the wireless communication based on the selected communication function, so that the operation by the controller 3 can not be performed. To avoid. The details of the process related to the selection control of the communication function will be described below with reference to the flowchart.

FIG. 3 is a flowchart showing a flow of processing relating to selection control of the communication function.
First, the environment identification unit 152 identifies the environment of the space around the work apparatus 1 by analyzing the image data captured by the imaging unit 12 (S1). For example, based on the size of the space around the specified work device 1, the environment specifying unit 152 selects one of the plurality of levels indicating the size of the space. For example, the environment specifying unit 152 selects a relatively high level when specifying that the surrounding space is wide, and selects a relatively low level when specifying that the surrounding space is narrow.

  When the image data captured by the imaging unit 12 includes an obstacle or the like, the work apparatus 1 is more likely to collide with the obstacle or the like, as in the case where the space is narrow. Therefore, based on the image data captured by the imaging unit 12, the environment identification unit 152 may determine whether the space around the work apparatus 1 includes an obstacle. When the environment specifying unit 152 determines that the obstacle is included, the environment specifying unit 152 selects one of the plurality of levels indicating the size of the space based on the size of the obstacle or the like. It is also good.

  Subsequently, the speed detection unit 154 detects the moving speed of the work device 1 (S2). For example, the movement mechanism 11 is provided with a sensor that measures the number of rotations of the wheel per unit time, and the speed detection unit 154 detects the movement speed of the work device 1 based on the number of rotations detected by the sensor. . Note that the speed detection unit 154 may detect the moving speed of the work device 1 based on the reception status of the operation command that instructs the movement of the work device 1.

  In this flowchart, after the environment of the space around the work apparatus 1 is specified, the movement speed of the work apparatus 1 is detected. However, the present invention is not limited to this, the environment of the surrounding space is detected after the movement speed is detected. The identification may be performed, or the detection of the moving speed and the identification of the environment of the surrounding space may be performed simultaneously.

  Subsequently, the calculation unit 155 calculates the allowable delay time based on the ease of the collision of the work device 1 with the obstacle. Specifically, the calculation unit 155 calculates the allowable delay time based on the identified space environment and the detected moving speed (S3). For example, the storage unit 14 stores in advance a table in which the level indicating the size of the space, the moving speed, and the allowable delay time are associated.

  The allowable delay time is defined based on the ease of collision of the working device 1 against an obstacle. That is, since it is necessary to receive an operation for avoiding the collision by the controller 3 before the work apparatus 1 collides with an obstacle, it is predicted that the time until the work apparatus 1 collides with the obstacle is expected to be short. The allowable delay time is set short. Further, when it is predicted that the time until the work device 1 collides with the obstacle is long, the allowable delay time is set long.

  Here, if the space is wide or the moving speed of the working device 1 is low, the possibility of collision with an obstacle is low even if the reception of the operation command is delayed. On the other hand, when the space is narrow or when the moving speed of the working device 1 is high, there is a high possibility of collision with an obstacle when the reception of the operation command is delayed. Therefore, the allowable delay time is set longer as the space is wider and as the movement speed is smaller. The calculation unit 155 calculates the allowable delay time by specifying the allowable delay time associated with the level indicating the specified space size and the detected moving speed.

  Note that a table in which the level indicating the size of the space and the allowable delay time are stored in advance in the storage unit 14, the calculating unit 155 determines the allowable delay associated with the level indicating the size of the space The time may be specified.

The calculation unit 155 stores an arithmetic expression for calculating the allowable delay time based on the level indicating the space size and the moving speed in the storage unit 14, and the allowable delay time is calculated based on the arithmetic expression. It may be calculated.
The calculation unit 155 outputs information indicating the calculated allowable delay time to the wireless communication unit 13.

  Subsequently, the prediction unit 131 of the wireless communication unit 13 predicts the future communication delay time of the wireless communication with the controller 3 (S4). Specifically, the prediction unit 131 predicts the communication delay time using a prediction formula for calculating the communication delay time based on time series data of the past communication delay time. Here, the storage unit 14 may use, for example, an AR model (Auto-Regressive model), an MA model (Moving Average model), an ARMA model (Auto-Regressive Moving Average model), an exponential smoothing method, a Brownian method, as a plurality of prediction formulas. Store the prediction formula based on etc.

  The prediction unit 131 selects a prediction equation suitable for the wireless environment of the work apparatus 1 from the plurality of prediction equations stored in the storage unit 14 and calculates communication delay time based on the prediction equation. For example, the prediction unit 131 specifies the power (received power) of the signal received by the work device 1 from the access point 2. Note that the prediction unit 131 identifies what environment the wireless environment of the work device 1 is based on the transmission power of the work device 1, modulation and coding scheme (MCS), etc., in addition to the received power. May be

  FIG. 4 is a diagram showing the correspondence between the wireless environment of the work apparatus 1, the measured values of the communication delay time, and the predicted values of the communication delay time calculated using each of the plurality of prediction formulas. In the storage unit 14, as shown in FIG. 4, the received power of the work apparatus 1 specified in the past by the prediction unit 131, the measured value of the communication delay time, and the prediction unit 131 each use a plurality of prediction formulas. The predicted value of the communication delay time predicted in the past and the difference between the actual measurement value and each predicted value are stored in association with each other.

  The prediction unit 131 refers to, for example, the information illustrated in FIG. 4 and selects a prediction formula with the smallest difference between the actual measurement value and the prediction value at received power close to the specified received power. Then, the prediction unit 131 estimates the communication delay time based on the selected prediction formula. In addition, the prediction part 131 may select the prediction formula with the smallest total value of the difference of an actual value and a predicted value, when multiple data of the same reception power as the identified electric power exist.

  Subsequently, the selection unit 132 performs wireless communication based on the allowable delay time calculated by the calculation unit 155 based on the ease with which the work device 1 collides with the obstacle and the communication delay time predicted by the prediction unit 131. The communication function regarding the wireless communication of the communication unit 13 is selected. Specifically, the selection unit 132 determines whether the predicted communication delay time is longer than the allowable delay time (S5). If the selection unit 132 determines that the predicted communication delay time is longer than the allowable delay time, the process proceeds to S6. If the predicted communication delay time is determined to be equal to or less than the allowable delay time, the process proceeds to S8.

  In S6, the selection unit 132 selects a communication function to reduce the communication delay time. For example, when the communication delay time is larger than the allowable delay time, the selection unit 132 selects a function to limit the number of times of retransmission of a packet to be transmitted by wireless communication as a communication function to reduce the communication delay time. For example, in the function of limiting the number of packet retransmissions, by interrupting the retransmission of packets that are likely to exceed the allowable delay time at an early stage, the transmission timing of packets to be transmitted after the packet is advanced to suppress communication delay. Do.

  Further, when the communication delay time is larger than the allowable delay time, the selection unit 132 may select the function of occupying the band in wireless communication for a predetermined period as the communication function of reducing the communication delay time. The function of occupying the communication band of the wireless communication is performed on the other communication terminal performing the communication of the wireless LAN via the access point 2 at an interval shorter than the waiting time for the other communication terminal to wait for the transmission of the signal. It is a function of transmitting a short signal indicating that data communication with a terminal different from another communication terminal is in progress over a predetermined period. As a result, since the other communication terminal waits for data transmission while continuing to receive the short signal, the work device 1 can occupy the band of wireless communication with the access point 2. The short signal is a signal whose data amount is equal to or less than a predetermined amount, and is, for example, an ack signal.

  The selection unit 132 determines whether communication in the wireless LAN is congested or not, and when it is determined that the communication is not congested, selects the function of limiting the number of times of packet retransmission, and the communication is performed. If it is determined that the network is congested, the function of occupying the bandwidth for a predetermined period may be selected.

  In addition, when the selecting unit 132 selects a function to limit the number of packet retransmissions and wireless communication with the controller 3 is performed based on the function, the predicted communication delay time is equal to the calculated allowable delay time. If larger, the function of occupying a band in wireless communication for a predetermined period may be further selected.

  In addition, the selection unit 132 selects one communication method from the plurality of communication methods performing wireless communication based on the allowable delay time calculated by the calculation unit 155 and the communication delay time predicted by the prediction unit 131. You may For example, the prediction unit 131 calculates the communication delay time of each of the plurality of communication methods. Then, when the communication delay time estimated based on the communication method currently used by the work device 1 is larger than the calculated allowable delay time, the selection unit 132 selects another communication method different from the communication method. Among the above, the communication delay time predicted is selected to be the communication method equal to or less than the allowable delay time.

For example, when the communication delay time predicted for the wireless LAN is larger than the allowable delay time and the communication delay time predicted for LTE is equal to or smaller than the allowable delay time, the selection unit 132 selects LTE as the communication scheme. . Further, the selection unit 132 determines that the communication delay time predicted for the wireless LAN using the communication band in the 2.4 GHz band is larger than the allowable delay time, and the communication predicted for the wireless LAN using the communication band in the 5 GHz band. If the delay time is equal to or less than the allowable delay time, a wireless LAN using a 5 GHz band communication band is selected as the communication method.
By doing this, the selection unit 132 can suppress the communication delay by selecting another communication method predicted to have a short communication delay time.

  In addition, the work device 1 normally selects LTE as the communication method, and enables communication using the wireless LAN when the communication delay time predicted for LTE is larger than the allowable delay time, Communication with the controller 3 may be performed using a wireless LAN. By doing so, the work device 1 can reduce its own power consumption by minimizing the communication using the wireless LAN.

  When the selection unit 132 selects the communication function or the communication method, the communication control unit 133 controls wireless communication based on the communication function selected by the selection unit 132, and performs communication with the controller 3 via the access point 2 (see FIG. S7).

  On the other hand, if the selection unit 132 determines in S5 that the predicted communication delay time is equal to or less than the allowable delay time, the process proceeds to S8 to determine whether the allowable delay time is significantly larger than the communication delay time. For example, when the communication delay time is equal to or less than a predetermined ratio of the allowable delay time, the selection unit 132 determines that the allowable delay time is significantly larger than the communication delay time. If the selection unit 132 determines that the allowable delay time is significantly larger than the communication delay time, the process proceeds to S9. If it is determined that the allowable delay time is not significantly large, the process according to the present flowchart ends.

In S9, the selection unit 132 selects a communication function that is unlikely to adversely affect surrounding communication terminals that perform wireless communication via the access point 2. For example, even when the allowable delay time is significantly larger than the communication delay time, the selection unit 132 selects the function of limiting the number of retransmissions of packets transmitted by wireless communication, and the number of packets flowing on the communication line decreases. You may do so.
Subsequently, the communication control unit 133 controls wireless communication based on the communication function selected by the selection unit 132, and performs communication with the controller 3 via the access point 2 (S10).

[Effect in the present embodiment]
As described above, the work device 1 according to the present embodiment calculates the allowable delay time, which is the communication delay time that the work device 1 can tolerate, based on the environment of the surrounding space, and wireless communication with the controller 3 Predict a future communication delay time, select a communication function related to wireless communication based on the calculated allowable delay time and the predicted communication delay time, and perform wireless communication based on the selected communication function Control.

  By doing this, the work device 1 performs communication such that, for example, the communication delay time of the wireless communication is shortened when the predicted communication delay time is longer than the allowable delay time calculated based on the surrounding conditions. You can choose the function. Therefore, the work device 1 can adjust the communication quality based on the surrounding situation, and can prevent the situation where the operation by the controller 3 can not be performed.

  In addition, since the work device 1 calculates the allowable delay time based on its own moving speed, the work device 1 can select the communication function related to wireless communication based on the allowable delay time and the communication delay time. Thereby, the work apparatus 1 can increase the possibility of receiving the operation command from the controller 3 without delay before the obstacle or the like existing in the movement destination of the work apparatus 1 collides, and the collision to the obstacle or the like is prevented. can do.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It is apparent to those skilled in the art that various changes or modifications can be added to the above embodiment. In particular, the specific embodiment of the distribution and integration of the devices is not limited to the one illustrated above, and all or part of the specific embodiments according to various additions or the like or according to the functional load, in arbitrary units. It can be configured to be distributed or integrated functionally or physically.

  For example, in the above embodiment, the wireless communication unit 13 includes the prediction unit 131, the selection unit 132, and the communication control unit 133. However, the present invention is not limited to this, and the control unit 15 may have these functions. It is also good.

DESCRIPTION OF SYMBOLS 1 ... Work apparatus, 11 ... Movement mechanism, 12 ... Photography part, 13 ... Wireless communication part, 131 ... Prediction part, 132 ... Selection part, 133 ... Communication control part , 14: storage unit, 15: control unit, 151: imaging control unit, 152: environment identification unit, 153: movement control unit, 154: speed detection unit, 155 .. · Calculation unit, 2 · · · Access point, 3 · · · Controller, S · · · Communication system

Claims (4)

A working device that performs work in response to remote control from a controller, and
An environment identification unit that identifies an environment of a space around the work device;
A calculation unit that calculates an allowable delay time that is an allowable communication delay time of the work device based on the environment of the space;
A prediction unit for predicting a future communication delay time of wireless communication with the controller via a predetermined wireless communication network ;
If it is determined that communication in the wireless communication network is not congested when the predicted communication delay time is larger than the calculated allowable delay time, the number of retransmissions of packets transmitted by the wireless communication is limited. A selection unit that selects a communication function that occupies a band for a predetermined period when a communication function is selected and it is determined that communication in the wireless communication network is congested ;
A communication control unit that controls the wireless communication based on the selected communication function;
Work equipment provided with The working device is a mobile body,
And a speed detection unit that detects the movement speed of the work device,
The calculation unit calculates the allowable delay time based on an environment of the space and the moving speed.
The working device according to claim 1. The selection unit selects one communication method from a plurality of communication methods for performing the wireless communication based on the allowable delay time and the communication delay time,
The communication control unit controls the wireless communication based on a selected communication method.
The working device according to claim 1. A communication control method, wherein a computer performing work in accordance with remote control from a controller controls wireless communication with the controller via a predetermined wireless communication network ,
Identifying an environment of space around the computer;
Calculating an allowable delay time, which is an allowable communication delay time, based on the environment of the space;
Predicting a future communication delay time of the wireless communication;
If it is determined that communication in the wireless communication network is not congested when the predicted communication delay time is larger than the calculated allowable delay time, the number of retransmissions of packets transmitted by the wireless communication is limited. Selecting a communication function and determining that communication in the wireless communication network is congested , selecting a communication function that occupies a band for a predetermined period ;
Controlling the wireless communication based on the selected communication function;
A communication control method comprising:

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